mirror of https://github.com/dmarkham/enumer.git
60 lines
1.9 KiB
Markdown
60 lines
1.9 KiB
Markdown
# Enumer
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Enumer generates Go code to get string names from enum values and viceversa.
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It is a fork of [Rob Pike’s Stringer tool](https://godoc.org/golang.org/x/tools/cmd/stringer)
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but adding a *"string to enum value"* method to the generated code.
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This is useful when you need to read enum values from the command line arguments, from a configuration file,
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from a REST API request... In short, from those places where using the real enum value (an integer) would
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be almost meaningless or hard to trace or use by a human
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For example, if we have an enum type called `Pill`,
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```go
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type Pill int
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const (
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Placebo Pill = iota
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Aspirin
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Ibuprofen
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Paracetamol
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Acetaminophen = Paracetamol
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)
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```
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executing `enumer -type=Pill` will generate a new file with two methods:
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```go
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func (i Pill) String() string {
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//...
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}
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func PillString(s string) (Pill, error) {
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//...
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}
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```
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From now on, we can:
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```go
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// Convert any Pill value to string
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var aspirinString string = Aspirin.String()
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// (or use it in any place where a Stringer is accepted)
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fmt.Println("I need ", Paracetamol) // Will print "I need Paracetamol"
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// Convert a string with the enum name to the corresponding enum value
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pill, err := PillString("Ibuprofen")
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if err != nil {
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fmt.Println("Unrecognized pill: ", err)
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return
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}
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// Now pill == Ibuprofen
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```
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The generated code is exactly the same as the Stringer tool plus the `<Type>String` method, so you can use
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**Enumer** where you are already using **Stringer** without any code change.
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## How to use
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The usage of Enumer is the same as Stringer, no changes were introduced.
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For more information please refer to the [Stringer docs](https://godoc.org/golang.org/x/tools/cmd/stringer)
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## Additional functions of this fork
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This fork additionally implements the Scanner and Valuer interface to use a enum seamlessly in a database model.
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## TODO
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- Add a flag to optionally generate implementation of Scanner und Valuer interface
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